In my project, I defined connectionString consists of MaxIdleTimeMS Property but some time max connection Idle time out does not work correctly as expect.

below is describle of test pattern i have executed:

context:

current connections number: 1
when I setting MaxIdleTimeMS=0 and operation screen to establish connection to DB

the curren connections number still 1 (as expect)

when I setting  MaxIdleTimeMS=5 and operation screen to establish connection to DB

the curren connections number : 2 (increase 1) 
but I have to waiting about 10 minutes for connection close (current connections number:1)

I don't know whether somewhere in C# driver source code has overwrite MaxIdleTimeMS value or not but, I can't accurately adjust the MaxIdleTimeMS number as expect.

If that is about my mistake, can someone give me some comment pls?